Device for threading bo



W. F. WALKER.

DEVICE FOR THREADING BOLTS.

(No Model.)

No. 299,299. Patented May 27, 1884.

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\VILLIAM F. WALKER, OF XVOROESTER, MASSACHUSETTS.

DEVICE FOR THREADING BOLTS.

SPECIFICATION forming part of Letters Patent No. 299,299, dated May 27, 188%.

Application filed January 4, 1884. (No model To all whom it may concern Be it known that I, WILLIAM F. WALKER, a citizen of the United States, residing at Vorcester, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Bolt Cutting Die- Ohueks; and I declare the following to be a description of my said invention sufficiently full, clear, and exact to enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

The object of my present invention is to provide a simple and efficient opening and closing bolt-cutting die-chuck which can be manufactured at comparatively small expense,

.and which is adapted for ordinary black smith s bolt-work, as well as for other classes of bolt-cutting; and my invention consists in a chuck and die mechanism constructed and operating, as illustrated in the drawings, and hereinafter more fully described.

Figure 1 is a front view of my improved bolt-cutting die-chuck. Fig. 2 is a transverse sectional view at the back of the face-plate, showing the arrangement of the dies for opening and closing and the adjustable stop (lo-- vices; and Fig. 3 is a longitudinal section through the plates and dies.

In the drawings, A designates the body or head piece of the chuck, provided. with a suitable hollow hub or extension, A, for connecting it with the hollow arbor of the bolt-thread ing machine when in use.

B B indicate the cutters or dies for cutting the screw-threads upon the bolt or rod, which is fed into the central opening of the chuck in the usual manner. Said dies B are fitted into suitable recesses or grooves formed in the face of the part A perpendicular to the axis, so that the dies can move in radial direction for opening and closing their jaws or cutting parts 7) upon the bolt. The dies 13 are provided near their rear ends with inclined slots or grooves c, for engaging with studs (Z d, which are fixed in the face-plate D, and by means of which said dies are opened and closed when plate D is given a slight rotative action about the body A. The face-plate D is made quite thin at the central part, c, where it rests upon the front of the dies B, while it is re-enforced or made with a thicker annular portion at e, for sustaining the studs cl cl, thus giving a strong, firm support for said studs,while permitting the dies to come well forward toward the front surface of the chuck. The studs (1 (Z are in the present instance screw-threaded in r the plate, so as to be readily adjusted or removed, if desired. The plate D is also provided with an annular rim or flange, D, that surrounds the headpiece A, in the manner indicated. Said rim D is screw-threaded at its rear part to receive a correspondinglythreaded flanged ring, E, which can be screwed down upon the back of the headpiece A, so as to draw the head and face-plate together, and thereby clamp the dies B firmly in position between the bottom of the guidinggroove in said head and the inner surface of the face-plate D. The flange of the ring E rests against the back of the head-piece, and said ring is provided with suitable handles, E, to facilitate the operation of turning it when clamping and unclamping the dies. The face-plate D is provided with openings to receive a handle or lever, G, by means of which said face-plate can be moved or rotated for opening and closing the dies by the action of the studs din the inclined grooves c. A conical-pointed screw-stud, I, is arranged in the face-plate rim D, which stud enters a recess, a, in the head A, and serves as a stop for the plate when the dies are closed or in. proper working position. By turning said screwstud in or out, the conical point is adjusted to strike the end of the recess a by a longer or shorter movement of the face-plate, thus regulating the extent of the opening and closing action of the dies in a very line and perfect manner, so that accuracy in the cutting of threads of uniform diameter is attained.

The studs d d are preferably made with conoidal points, and the sides of the grooves or slots 0 beveled or slanted, so that by adjusting the studs any looseness or backlash between the dies and their operating parts can be taken up.

The dies B can be changed for different sizes by unscrewing the ring E and removing leaving the dies free to be lifted from the grooves or guiding-recesses. For small-sized dies the guiding-grooves can be reduced by placing a strip or strips of metal within said grooves alongside the dies, thus obviating'the necessity of making the dies with as large a body as those for cutting larger bolts, and to a proportional extent reducing the cost of such dies.

In the operation'of my improved chuck the dies are closed by turning the plate forward until the stud I strikes'the end of its recess a, and the ring E is then screwed up to clamp the dies firmly in position against the faceplate. The rod is entered at the axial opening, the machine started, and the thread cut for any required distance. then stopped, the ring turned back sufficient to loosen the clamp of the dies, and then, by inserting the lever G and turningback the I face-plate,the dies areopened or separated, so

that the bolt-thread is released from the jaws of the dies without the necessity of running them back over the screw-thread which has been formed on the bolt.

I am aware that bolt-cutting chucks having opening and closing dies have heretofore been employed; but, so far as I have knowledge, such devices are all comparatively expensive for manufacture, and are essentially different in construction and operation from the mechanism herein described and claimed.

The machine is What I claim as of my invention, and desire to secure by Letters Patent, is

1. The combination of the die-supporting head, the radially-moving dies having inclined slots in their surface, a face-plate provided with studs which enter said slots, adapted for moving the dies by rotative action of said plate, and a screw-threaded ring for clamping said dies at positions of adjustment between the head and plate, substantially as set forth.

2. The combination of the head-piece A, the dies B, guided and supported in said head, the face-plate D, having studs d d engaging with inclined slots in said. dies, and the ring E, screw-threaded to said face-plate and bearing against said head-piece, substantially as and for the purpose set forth.

3. A conicallypointed screw-stud, as I, in combination with the dies and diesupporting head, having a recess, as a, and the rotative face-plate D, substantially as and for the purpose set forth. 7

4. The combination, with the head A and dies B and die-operating studs d d, of a faceplate having a thin central portion, e, and annular re enforce or thicker portion 0, substantially as and for the purposestated.

Witness my hand this 31st day of December, A. D. 1883.

WILLIAM F. XVALKER.

Witnesses:

CHAS. H. BURLEIGH, GEo. M. REED. 

